1. Field of the Invention
The invention relates to the use of chelating agents having active nitrogen and oxygen chelating atoms which form insoluble chelates with metals, for the recovery of metal values from ores by flotation and oil extraction flotation techniques and more particularly relates to the use of .alpha. and .beta. hydroxyoximes and the like as reagents in such separatory methods.
2. Brief Description of the Prior Art
Although it is a general practice to beneficiate oxide type copper ores through hydrometallurgical methods, flotation beneficiation of oxide ores is possible after a sulfidization treatment using xanthates as collectors. However, flotation methods using xanthates and sulfidizers such as sodium sulfide have not been entirely satisfactory and to date such methods are not a commercial reality. Xanthate, by itself, cannot efficiently collect oxide copper minerals such as chrysocolla and a preliminary sulfidization does not always lead to success; excess sulfide being, in fact, detrimental. Other conventional types of collectors such as fatty acids and sulfonates have also proved unsuccessful as collectors for flotation of oxide copper ores. In addition, the latter types of collectors do not collect sulfide copper minerals.
Often, copper-bearing ore materials have to be ground to a fine size for processing or have to be mined in the form of fines or so-called "slimes". For example, the sodium chloride contaminated sea-bottom deposits contain mineable quantities of copper but are in the form of a slime. Prior art flotation methods using the heretofore known collectors have proved to be both inefficient and uneconomical to recover metal values from fines or slimes.
Clearly, there is a need for "flotaids", i.e.; collectors, modifiers, promotors and activators to improve the flotation of copper ores, both oxide and sulfide types. These flotaids must function efficiently to recover copper values from fines or slimes. It is further highly desirable that the flotaids be selective for copper minerals over the other associated minerals and gangue, irrespective of the size of the ore particles. The choice for such a flotaid would be a reagent which is specific and selective for copper over other metals. We have found a class of compounds which meet these requirements and which function as flotaids for copper in the flotation of copper ores and like procedures.